AB-INITIO POTENTIAL-ENERGY CURVES OF RYDBERG, VALENCE AND CONTINUUM STATES OF NO

Bound states and quasibound Rydberg states of NO are studied as a func tion of internuclear distances in the range 1.6-3.024 a(0). R-matrix c alculations which include 12 configuration interaction target states i n the close-coupling expansion are performed. Rydberg states of up to n = 10 are studied for the (2) Sigma(+), (2) Pi and (2) Delta symmetri es of NO. Intruder states, of both valence and Rydberg character, are followed both above and below the ionization threshold. Where possible these states are classified as Rydberg states of an excited state of the ion. Away from avoided crossings, it is found that the quantum def ects of the Rydberg series converging on the X (1) Sigma(+) state of N O+ show little sensitivity to bondlength but show considerable depende nce on the number of states included in the close-coupled expansion.